Southern California taxi driver Gurmukh Singh faces deportation by the U.S. Immigration and Customs Enforcement agency. His request for asylum was turned down 18 years ago, and he has been trying ever since to get the decision reversed. In early May, the husband of an American wife and father of two teenage daughters was detained.

That's when his congressman, Representative Alan Lowenthal, stepped in and filed a private immigration bill that would legalize Singh's status.

While members of Congress can intervene in individual immigration cases, the process recently became harder as the Trump administration changed the way immigration authorities approach such cases.

What is a private bill?

A private bill is a piece of legislation creating a law affecting a particular individual or a small group of people. Such bills can provide relief from another law, grant a unique benefit or relieve someone from legal responsibility for an allegedly wrongful act. Often, members of Congress introduce these bills to address the status of individuals who have exhausted all their other options in the U.S. immigration system.

How often does this happen?

Private bills are not commonly used. Between 1986 and 2013, 94 private bills were enacted. Almost 300 private bills have been introduced since 2010, says Jill Marie Bussey, the advocacy director of the Catholic Legal Immigration Network. She says the actual number of those enacted will be small.

"They're like Hail Mary passes," Bussey added, "It's a situation of last resort."

What are the changes to private bills?

In the past, ICE would delay deportations of undocumented immigrants with private bills pending in Congress — about 70 cases in the last six years, according to the agency. But in May 2017, ICE informed Congress it would only defer deportations for up to six months and only after receiving a written request by the chair of the House and Senate judiciary committees or one of their subcommittees. Committee chairs are usually members of the majority party.

ICE says that the majority of private bills are intended to confer lawful permanent resident status by "circumventing the normal immigration law framework."

Bussey says that private bills are used infrequently and only in situations when there's no way to resolve the immigration case under current law.

"This is not about circumventing," she said, "this is about providing protection in very unique ways."

Robert Law, director of government relations at the Federation for American Immigration Reform, says the changes will make for a fairer process. "This is truly an example of individualized, case-by-case analysis and discretion," he said about private bills.

But some members of Congress feel the guidance upsets the balance of power.

"This is a mean-spirited action that tramples firm, longstanding practice between two coequal branches of government," said Dianne Feinstein and Dick Durbin, the ranking Democrats on the Senate Judiciary Committee and the Immigration Subcommittee.

Can members of Congress still intervene?

Members of Congress can still impact immigration cases in other, less formal ways. Bussey says members can call a local ICE office to get involved in a deportation or the U.S. State Department, when a case involves visa issues.

"There's human error in all of this stuff," said Bussey. "Even doing everything the right way, you know you've completed the forms properly, you know you've completed the case, things can go wrong."

That's exactly how freshman Representative Charlie Crist, a Democrat from Florida, was able to assist the Huynhs, longtime family friends who run a jewelry store in his district. He told VOA about walking into their store last Christmas to discover an emotional Mrs. Huynh.

"She was telling me about her daughter Kim who had gotten married a year prior and yet her husband wasn't allowed to come [from] Vietnam to be with her in America," Crist said. He joined Florida Senator Marco Rubio, who was already making regular phone calls to the State Department.

In the end, State Department officials interviewing Kim's husband spotted a picture of Crist in Kim's Saigon apartment and asked if he was a family friend. Three days later, he had his visa.

Where are lines drawn?

The responsibilities for regulating immigration are divided between Congress and the executive branch.

"Deferred action and parole are meant to be very, very limited, under very narrow circumstances," Law said. "There needs to be that clear line about what the letter of the law is and, if there are problems with the law, then we have a legislative process to fix it."

Bussey says that when members of Congress get personally involved in immigration cases, they learn more about "what's going on with these agencies, what people are facing day to day and, hopefully, they can learn from that."

Katherine Gypson is a reporter for VOA’s News Center in Washington, D.C. Prior to joining VOA in 2013, Katherine produced documentary and public affairs programming in Afghanistan, Tunisia and Turkey. She also produced and co-wrote a 12-episode road-trip series for Pakistani television exploring the United States during the 2012 presidential election. She holds a Master’s degree in Journalism from American University. Follow her @kgyp